In certain vehicle accidents, it may be difficult, impossible, or unsafe to exit from the doors of the vehicle. In a vehicle roll-over, for example, one door is under the cab and the other door facing upward. In heavy trucks especially, the weight of the door makes it difficult to lift open and hold open, both for an emergency responder and more so for a vehicle occupant attempting this from the inside of the vehicle cab. Egress through the windshield frame may be the fastest and safest alternative.
The windshields in heavy trucks may be designed so that the windshield can be kicked out in the event exit from the doors is difficult or unsafe. If the driver or passenger is not able to kick out the windshield, however, response team personnel must attempt to remove the windshield with tools, usually by cutting it out. This is laborious and time-consuming, and may pose a safety concern, for example, if there is a fire in or around the vehicle, or if the occupants of the vehicle are in need of immediate medical attention.
Methods for dislodging or removing windshields, windows, and doors are known. For example, U.S. Pat. No. 3,737,193 to Cain discloses a collapsed tube disposed about a periphery of a windshield and connected to a high pressure fluid source that inflates the tube when an impact sensor senses the vehicle has been in a collision. Expansion of the tube dislodges the windshield from its mounting. U.S. Pat. No. 3,741,583 to Usui et al. discloses a pyrotechnic device that releases or destroys a windshield or window in a vehicle using the vehicle airbag triggering system to activate it.
While the art discloses systems that activate upon sensing a collision or impact on the vehicle, none are known that respond to a vehicle roll-over, which involves different dynamics than front end or side collisions. For example, an event leading to a roll-over may begin with a front end collision, which in prior system may trigger the windshield release system before event concludes, that is, before the vehicle comes to a rest. The dislodged windshield, now movable, may then pose a danger to the vehicle occupants. As another example, a roll-over may result from a driver attempting a curve at too high a rate of speed, which may involve no frontal collision and a side impact that may not be sufficient to trigger the system.
The invention provides a system for dislodging a vehicle windshield from its mounting automatically upon a vehicle roll-over event.
According to an embodiment of the invention, a system for detaching a windshield from a vehicle cab, comprises a pressure applying device mounted between a windshield and a frame element, a roll-over condition sensor, and a controller connected to receive a signal indicating a roll-over condition from the roller-over condition sensor and connected to activate the pressure applying device responsive to receiving said signal.
The invention, according to another aspect, may further comprise an acceleration condition sensor, the controller being connected to receive a signal indicating an acceleration condition from the acceleration condition sensor, and further configured to activate the pressure applying device responsive to receiving the roll-over condition signal and the acceleration condition signal. According to a preferred embodiment, the acceleration sensor generates a signal when vehicle acceleration ends, that is, when the vehicle has come to a rest. The acceleration sensor may alternatively or in addition be configured to detect a collision event, as in vehicle airbag systems.
In addition or alternatively, the controller is configured with a delay function to delay activating the pressure applying device for a predetermined time period following receipt of a signal indicating a roll-over condition from the roller-over condition sensor.
According to an alternative embodiment, a system of the invention includes the controller being connected to a vehicle device controlling deployment of a vehicle airbag system to receive a signal indicating deployment of the airbag. The controller is configured to use both the roll-over condition sensor and the airbag deployment sensor to trigger the pressure applying device.
According to the invention, a pressure applying device comprises at least one pyrotechnic device. A mounting device for a pyrotechnic device includes a frame element that contains and directs the energy from activated the pyrotechnic device toward the windshield to weaken or break the securing elements.
Alternatively, a pressure applying device comprises an inflatable tube and a gas generating device connected to inflate the tube upon receipt of a signal from the controller.
Other pressure applying devices may be employed, as the invention is not directed to a particular pressure applying device.